Schottky diodes, used extensively in discrete digital and analog semiconductor devices and integrated circuits, comprise a solid-state junction formed by metal-semiconductor contact. Such diodes are typically fabricated from n-type or p-type material and metal. The metal is normally evaporated or sputtered onto the doped material at low temperatures to form a Schottky-diode junction at the metal-semiconductor interface. Conventional Schottky diodes are characterized by extremely rapid switching capability and have been used at high and ultrahigh frequencies as mixers, harmonic generators, detectors and the like. Schottky-diode junctions are also used in the manufacture of depletion- and enhancement-mode field effect transistors.
Schottky diodes normally have relatively low turn-on voltages, low breakdown voltages and significant forward leakage currents at only a few tenths of a volt (V). These features, while satisfactory in some applications, limit the usefulness of conventional Schottky diodes in electrical and optical applications where high power, low-leakage current and/or low noise are required. Those concerned with the development and application of Schottky diodes have long recognized the need to improve their high-power, low-noise performance characteristics. The present invention fulfills this need.